Monastery

A monastery is a community of persons, especially monks or nuns , bound by vows to a religious life and often living in partial or complete seclusion.
A monastery is also the the dwelling place of such a community. A monastery is the habitation of monks, derived from the Greek word for a hermit's cell. The word monastery comes from the Greek "monasterion", from the root "monos" = one, or alone (originally all Christian monks were hermits).

Christian monasteries are also called abbey, priory, charterhouse, friary, and preceptory, while the habitation of nuns can also be called a convent.
The communal life of a monastery is called cenobitic, as opposed to the anchoretic (or anchoritic) life of an hermit.

Orthodox Christian Monasteries

Christian cenobitic monasticism started in Egypt. Originally, all Christian monks were hermits, and especially in the Middle East this continued to be very common until the decline of Syrian Christianity in the late Middle Ages. But not everybody is fit for solitary life, and numerous cases of hermits losing their grips are reported.

The need for some form of organized spiritual guidance was obvious, and around 300 St. Anthony started to organize his many followers in what was to become the first Christian monastery. After Anthony, and on his advice, Saint Amun gathered up his solitaries into a single rule. Soon the Egyptian desert, especially around Nitria, which was called the "Holy City," abounded with similar institutions.

The idea caught on, and other places followed:
Mar Awgin founded a monastery on Mt. Izla above Nisibis in Mesopotamia (~350), and from this monastery the cenobitic tradition spread in Mesopotamia, Persia, Armenia, Georgia and even India and China.

Orthodox Christian Monasteries

In the Eastern Orthodox Church, monks and nuns follow a similar ascetic discipline. Unlike Roman Catholics, there is only one form of monasticism for the Orthodox. Monastics, male or female, live lives away from the world, in order to pray for the world. They do not run hospitals and orphanages, they do not teach or care for the sick; it is expected for lay people to do these things to work out their own salvation. Monasteries can be very large or very small. The largest monasteries can hold many thousands of monks and are called lavras. Small monasteries are often called “sketes” and usually only have one elder and 2 or 3 disciples. There are higher levels to ascetic practice but the monks who practice these do not live in monasteries, but alone. When monks live together, work together, and pray together, following the directions of the abbot and the elder monks, this is called a cenobium. The idea behind this is when you put many men together, like rocks with sharp edges, their “sharpness” becomes worn away and they become smooth and polished.

One of the great centers of Orthodox monasticism is the Holy Mountain (also called Mt. Athos) in Greece, an isolated, self-governing peninsula approximately 20 miles long and 5 miles wide (similar to the Vatican, being a separate government), administered by the heads of the 20 major monasteries, and dotted with hundreds of smaller monasteries, sketes, and hesicaterons. Even today the population of the Holy Mountain numbers in the tens of thousands of monastics (men only) and cannot be visited except by men with special permission granted by both the Greek government and the government of the Holy Mountain itself.